title: Decrease in xenon clearance during response to cold, dry air: problems of interpretation.
abstract: In order to increase our understanding of the nasal response to cold, dry air (CDA), we studied changes in xenon clearance as an indicator of nasal blood flow. Eight individuals previously shown to respond to CDA had measurements of xenon clearance made in the left inferior turbinate before, during, and after a 15-minute exposure to either CDA (-7 degrees C to 0 degrees C, less than 10% relative humidity) or room air. The half-life in seconds for xenon clearance on the day when CDA was inhaled was 56 +/- 6, 41 +/- 5, and 110 +/- 31, before, during, and 10 minutes after challenge, respectively. On the control day, with subjects breathing room air, the equivalent measurements of half-life in seconds were 54 +/- 8, 41 +/- 6, and 42 +/- 4, respectively. Xenon clearance was prolonged significantly (p less than .01) after exposure to CDA during the clinical response. The interpretation of the change in xenon clearance as an indicator of nasal blood flow is discussed.
authors.affiliation: Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: R M
authors.initials: RM
authors.lastname: Naclerio
authors.forename: C
authors.initials: C
authors.lastname: Fisher
authors.forename: C A
authors.initials: CA
authors.lastname: Civelek
authors.forename: D
authors.initials: D
authors.lastname: Bartenfelder
authors.forename: D
authors.initials: D
authors.lastname: Koller
authors.forename: N D
authors.initials: ND
authors.lastname: La France
mesh_terms: D000388:Air; D000704:Analysis of Variance; D001783:Blood Flow Velocity / Q000187:drug effects; D002196:Capillaries; D003080:Cold Temperature; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D006813:Humidity; D009666:Nose / Q000098:blood supply* / Q000502:physiology; D010109:Oxymetazoline / Q000494:pharmacology; D011897:Random Allocation; D012039:Regional Blood Flow; D014980:Xenon Radioisotopes
chemical_list: D014980:Xenon Radioisotopes; D006632:Histamine; D010109:Oxymetazoline